1. Technical Field
The present invention relates to a printing device and a method for controlling a printing device.
2. Background Technology
An inkjet printer is known in which printing is conducted by feeding paper in one direction, moving a head having a plurality of nozzles back and forth in another direction perpendicular to the one direction, and ejecting ink of each color from each of the nozzles. In the inkjet printer, when a state in which ink is not ejected from the nozzles lasts, there are cases in which the moisture of ink evaporates from the openings of the nozzles so as to increase the viscosity of ink. When the viscosity of ink is increased, there are cases in which clogging of the nozzles occurs and the ejection operation of ink becomes unstable. In order to avoid these situations, as shown in Japanese Laid-open Patent Publication No. 2010-58348, for example, an apparatus has been proposed to prevent or solve clogging of the nozzles. In such an apparatus, an ejection operation (flushing process) for ejecting ink which does not contribute to image formation is conducted from each of nozzles to a feed belt for feeding paper. Also, a flushing process in which ink is ejected to paper while being dispersed so as not to be observed has been known. For example, in a case in which a plurality of pages in one job include both color printing and monochrome printing, flushing (between-paper flushing) for ejecting color ink to a feed belt is conducted at a timing when printing to a prescribed page is completed and printing to the next page is started so as not to increase the viscosity of ink in a nozzle for ejecting color ink at the time of continuing monochrome printing. Also, even in a case of monochrome printing, the viscosity of color ink in a nozzle can be prevented from increasing by conducting flushing of color ink on paper (on-paper flushing).